A number of diseases, medical or trauma conditions give rise to cosmetically undesirable pigmentary variation in human skin. Scars, temporary or permanent hypo- and hyper-pigmentation, striae (stretch marks), leukoderma, poikiloderma of Civatte, etc., are examples of conditions in which a melanin pigmentation cosmetic defect is presented by at least one component of the condition. A variety of approaches have been used to reduce the contrast between pigment variation regions, including chemical etches (“peel”), dermabrasion, laser ablation, and UV light sources.
Prior approaches for dealing with these conditions included removing the abnormally pigmented skin, or a portion of such skin with the goal of promoting new growth that contains cosmetically desirable “natural” pigmentation. Another approach provided for treating skin with UV light sources to promote the formation of melanin in melanin-deficient skin.
Ablative laser skin resurfacing, chemical peels and dermabrasion are examples of some approaches used for removing skin. UV lamps and excimer laser therapies are examples of some types of UV light sources.
Prior approaches have suffered from a lack of good control over the pigment induction. One shortcoming frequently associated with removing abnormally pigmented skin is that pigment-deficient areas of skin frequently exhibit resistance to melanogenesis or pigment induction. Thus, even after removing a portion of the pigment-deficient area of skin, and generating new growth of skin, the pigment deficiency frequently persists. In connection with providing UV treatment to pigment deficient skin, difficulties are also realized in that the spatial localization of the treatment is difficult to control and results in less than desirable outcomes.